排序方式: 共有45条查询结果,搜索用时 15 毫秒
31.
In this study, we propose and validate social networks based theoretical model for exploring scholars’ collaboration (co-authorship) network properties associated with their citation-based research performance (i.e., g-index). Using structural holes theory, we focus on how a scholar’s egocentric network properties of density, efficiency and constraint within the network associate with their scholarly performance. For our analysis, we use publication data of high impact factor journals in the field of “Information Science & Library Science” between 2000 and 2009, extracted from Scopus. The resulting database contained 4837 publications reflecting the contributions of 8069 authors. Results from our data analysis suggest that research performance of scholars’ is significantly correlated with scholars’ ego-network measures. In particular, scholars with more co-authors and those who exhibit higher levels of betweenness centrality (i.e., the extent to which a co-author is between another pair of co-authors) perform better in terms of research (i.e., higher g-index). Furthermore, scholars with efficient collaboration networks who maintain a strong co-authorship relationship with one primary co-author within a group of linked co-authors (i.e., co-authors that have joint publications) perform better than those researchers with many relationships to the same group of linked co-authors. 相似文献
32.
33.
The current research examined how seeking versus receiving help affected children's memory and confidence decisions. Baseline performance, when no help was available, was compared to performance when help could be sought (Experiment 1: N = 83, 41 females) or was provided (Experiment 2: N = 84, 44 females) in a sample of predominately White 5-, 7-, and 9-year-olds from Northern California. Data collection occurred from 2018 to 2019. In Experiment 1, 5-year-olds agreed most often with sought-help, whereas 9-year-olds were the only age group reporting lower confidence for sought-help relative to baseline trials. In Experiment 2, agreement and confidence after provided help were similar across age groups. Different developmental patterns when help was sought versus provided underscore the importance of active help-seeking for memory decision-making. 相似文献
34.
35.
Alireza Behtoui 《British Journal of Sociology of Education》2019,40(3):340-356
Recent research demonstrates that, along with the family, the peer group and the school environment, extra-curricular activities are important contexts for young people’s educational and social development. This article is the result of a survey conducted with a sample of young people in their last year of compulsory school in Sweden and examines both who has access to the different types of extra-curricular activity and the consequences of their participation in the various programmes. As the results indicate, after controlling for respondents’ class and migrant background, their gender and their health, there are positive and significant associations between participation in certain types of activity (sporting, cultural and religious) on the one hand, and students’ school performance and educational expectations on the other. However, attendance at a less-organised activity (youth recreation centres or fritidsgård) shows a negative association with these outcomes. Furthermore, the results demonstrate that the gender, social class and migrant background of students affect their rate of participation in many of these activities. 相似文献
36.
Alireza Nakhaee Mohammad Bokaeian Mohsen Saravani Ali Farhangi Azim Akbarzadeh 《Indian journal of clinical biochemistry : IJCB》2009,24(4):419-425
In traditional medicine, Eucalyptus globulus (eucalyptus) was used for the treatment of diabetes mellitus. Hyperglycemia in
diabetes has been associated with increased formation of reactive oxygen species (ROS) and oxidative damage to tissue compounds.
The aim of this study was to evaluate the effects of eucalyptus in the diet (20 g/Kg) and drinking water (2.5 g/L) on lipid
peroxidation, protein oxidation and antioxidant power in plasma and liver homogenate, as well as glycated-Hb (HbA1C) of blood in streptozotocin-induced diabetic rats for a period of 4 weeks. Diabetes induced in rats by a single intraperitoneal
injection of streptozotocin (STZ, 65 mg/Kg). At the end of the treatment period, the level of plasma glucose, plasma and liver
malondialdehyde (MDA, the main product of lipid peroxidation), protein carbonyl (PC, one of the protein oxidation products)
and HbA1C increased and ferric reducing antioxidant power (FRAP) decreased in diabetic rats compared to normal rats. Eucalyptus administration
for 4 weeks caused a significant decrease in the plasma glucose levels, plasma and liver MDA, PC and HbA1C, also a concomitant increase in the levels of FRAP in diabetic treated rats. In conclusion, the present study showed that
eucalyptus posses antioxidant activities. Eucalyptus probably restores antioxidant power, due to the improved hyperglycemia
in streptozotocin-induced diabetic rats. 相似文献
37.
38.
39.
Zahra Saffari Maryam Farahnak Zarabi Hasan Aryapour Alireza Foroumadi Ali Farhangi Soheil Ghassemi Azim Akbarzadeh 《Indian journal of clinical biochemistry : IJCB》2015,30(2):140-149
Chemotherapy drugs, used for prevention of uncontrolled cell proliferation in certain tissues as well as inducing apoptosis in tumor cells, are important candidates for treatment of cancer. The synthesized 2-amino-4H-chromene-3-carbonitrile derivatives effective on cancerous cells resistant to other drugs such as Paclitaxel were used due to their ability in induction of apoptosis. The growth inhibitory and inducing apoptosis activities were determined. In order to make it target-oriented, the best compound was conjugated with gold nanoparticles (NPs) by aspartic acid with chemical reduction method. Cytotoxicity effect of 2-amino-4H-chromene-3-carbonitrile derivatives against the T47D breast cancer cell line was determined by MTT assay. The synthesis of gold NPs was confirmed by transmission electron microscopy, UV–Vis and dynamic light scattering. To assess the effects of compounds on the process of apoptosis, staining methods with acridine orange–ethidium bromide and Hoechst staining by fluorescence microscopy and DNA fragmentation by the diphenylamine method were used. The synthesized compounds containing two NH2 groups on benzene rings, demonstrated more cytotoxicity effect. The effect of conjugation with gold NPs and the induction of apoptosis were studied with the best compound. The cytotoxicity effects of the synthesized 2-amino-4H-chromene-3-carbonitrile compounds were changed by replacement of NO2 group on thiol ring with different chemical groups on the benzene ring. Analyses of treated cell lines by conjugated and non-conjugated forms of compounds verified their ability in inducing apoptosis while conjugated form demonstrated higher apoptosis. 相似文献
40.
Mehri Shahbazi Abdolhossein Farajpahlou Farideh Osareh Alireza Rahimi 《Library & information science research》2019,41(1):78-84
A credible scale based on the opinions of system users was developed to evaluate and assess data quality in automated library systems (ALS). Development and testing were carried out in two stages. In the first stage, 77 dimensions for data quality which had been previously identified through a systematic literature review were used to develop scale items. The first draft of the scale was then distributed among a target population of ALS experts to solicit their opinions on the scale and the items. In the second stage, a revised version of the scale was distributed among the main study population, which included end users of the target systems. This stage used factor analysis to determine the final draft of the scale, which consists of 4 factors and 62 items. The 4 factors were named after the qualities of their associated items: Data Content Quality, Data Organizational Quality, Data Presentation Quality, and Data Usage Quality. This scale can help system managers identify and resolve potential problems in the systems they manage and can also aid in evaluating the quality of data sources based on the opinions of end users. 相似文献